Frozen pipe prevention

Which pipes freeze first

Freezing is about where the pipe is, not how cold it gets outside. Water in a pipe surrounded by heated air almost never freezes. Water in a pipe that sits in an uninsulated cavity, with wind washing the other side of the sheathing, freezes fast.

In order of how often they fail here:

• Hose bibs and exterior spigots, especially with a hose still attached. Even frost-free bibs cannot drain with a hose on them.
• Pipes in exterior walls, particularly under kitchen and bathroom sinks on an outside wall.
• Crawlspace and unheated basement runs, where an open vent or a missing skirt lets cold air circulate.
• Attic plumbing, including runs to a second-floor bath and any pipe above the insulation line.
• Unheated garages, where a water heater, utility sink or line to an exterior spigot often lives.
• Vacant or seasonally unoccupied homes, where the thermostat got turned too far down.

Colorado's daily temperature swings make it worse. A 40-degree shift between afternoon and night is ordinary here, so pipes in unconditioned space get cycled hard rather than sitting at a steady temperature.

Before the first hard freeze

The first hard freeze in the Colorado Springs area usually arrives in early-to-mid October, so this work belongs in September.

• Disconnect every hose. This one action prevents more burst spigots than anything else on the list.
• Shut off the interior valve to each hose bib, then open the outside spigot to drain it and leave it open all winter.
• Blow out the sprinkler system in September, including the backflow preventer.
• Insulate exposed pipe in crawlspaces, garages, attics and unheated basements with foam sleeves sized to the pipe.
• Seal air leaks where pipes pass through exterior walls, rim joists and the foundation. A small gap with wind behind it does more damage than the ambient temperature.
• Close crawlspace vents and confirm access doors latch shut.
• Add heat tape or heat cable to problem runs that have frozen before, following the manufacturer's instructions on a proper outlet.
• Find and tag the main shutoff so everyone in the house knows where it is.

During a cold snap

When a hard freeze is forecast, open cabinet doors under sinks on exterior walls so room air reaches the pipe. Hold the thermostat steady day and night rather than setting back deeply overnight — the savings are not worth a burst line. If you are leaving town, set the heat no lower than the mid-50s and have someone check the house.

Let a faucet on the most vulnerable run drip. Moving water resists freezing, and an open faucet gives expanding ice somewhere to push. A pencil-lead stream is enough.

If a pipe is frozen but not burst

The signs are a faucet that gives only a trickle or nothing at all while others work normally, frost or bulging on a visible pipe, and sometimes a faint odor from a drain. If you catch it before the pipe splits, you can often save it.

1. Open the faucet the frozen line feeds, both hot and cold sides. This relieves pressure and gives meltwater a path out.
2. Find the frozen section. Follow the line from the faucet back toward unheated space and feel for the cold spot.
3. Apply gentle heat starting at the faucet end and working back toward the blockage. A hair dryer, a heating pad wrapped around the pipe, or towels soaked in hot water all work.
4. Never use a torch, propane heater or open flame. It is the leading cause of house fires during cold snaps, and it can flash trapped water to steam and rupture the pipe.
5. Keep going until full pressure returns, then leave the faucet dripping for a while.
6. Check the whole run for leaks afterward, including inside cabinets and the ceiling below.

If you cannot reach the frozen section, if it is inside a wall, or if heat is not restoring flow, stop and call a plumber. Pipe inside a wall needs a different approach and often needs to be opened up.

When to shut off the main

Shut off the main immediately if water is coming out anywhere it should not be, if you hear running water with every fixture closed, or if a pipe is visibly split or bulging. Shut it off before you start investigating, not after.

Also shut it off if you are leaving a house empty in winter and cannot guarantee heat, and if a frozen pipe thaws while you are away — the burst only reveals itself when the ice melts.

Your main shutoff is usually where the service line enters the house, often in a basement or crawlspace near the front wall, or in a utility closet. Know which way it turns and make sure the valve actually moves — old gate valves seize, and finding that out during a flood is the wrong time. If yours will not turn, have it replaced. Smith installs accessible shutoffs as part of main shutoff and leak detection work.

What a licensed plumber does that you can't

A homeowner can insulate, drain and thaw accessible pipe. What a plumber brings is everything behind drywall.

They thaw pipe inside walls and under slabs without opening the whole assembly, using equipment designed for it. They locate hidden leaks with acoustic and thermal tools, which matters because a pipe that froze and split often leaks slowly inside a cavity for weeks before it shows on a ceiling. They evaluate whether a line that keeps freezing should be rerouted into conditioned space — the permanent fix, versus insulating the same bad run every year.

They also handle repiping where old galvanized or cast iron supply lines have thinned — common in Old Colorado City and the Westside, and those thinned lines split first. After any freeze event, a professional check of the full run is worth it even when everything looks fine.

Frequently asked questions